Flat knitting machine with multiple carriages

ABSTRACT

Several flat needle beds of a knitting machine are arranged along a loop-shaped path in which many knitting carriages travel in a continuous row in the same direction. Individual carriages are switched automatically from the path to a holding area and returned from the holding area to the loopshaped path as may be required for producing a desired pattern and for replenishing yarn on the carriage.

United States Patent Krause 51 Aug. 14, 1973 FLAT KNITTING MACHINE WITH 3,456,459 7/1969 Doughty 66/60 x MULTIPLE CARRMGES FOREIGN PATENTS OR APPLICATIONS 1 lnvemo" Erich Krill", 653,552 3/1965 Belgium 66/64 Bopfingen, Germany v r 73 Assignee: Universal Maschinenfabrik Dr. Primary examiner-Ronald Feldbaum Rudolf Schieber KG, Westhausen, 148mm"! Exammerl3 Germany Attorney-Kelman & Berman d: [22] File June 8 1971 ABSTRACT [211 App! lsloss Several flat needle beds of a knitting machine are arranged along a loop-shaped path in which many knit- [52] 0.8. CI. 66/64 g carriages travel in a continuous row in t sam di- [51] Int. Cl D04b 7/04 reetion- In ivi rri g r wit h omatically [58] Field of Search 66/64, 60 from the pa h t a holding a an returned fr m th holding area to the loopshaped path as may be required [56] References Cit d for producing a desired pattern and for replenishing Mehwert 66/64 yarn on the carriage.

10 Claims, 13 Drawing Figures PATENTEDAUB'I M913 3,751,944

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INVENTORI E Kraus BYI ' Fig.12 73 mwiNmR; EHO Kyaugk FLAT KNITTING MACHINE WITH MULTIPLE CARRIAGES 1 This invention relates to a flat knitting machine adapted for the simultaneous knitting of several pieces of fabric, and particularly to a knitting machine having a plurality of flat needle beds arranged along a loopshaped path in which a plurality of knitting carriages travel substantially continuously in the same direction during operation ofthe machine.

Flat knitting machines are capable of producing fabrics of varying width which are free from distortion, and they provide a wide variety of knitted patterns, being superior to circular knitting machines in these respects. It was a common disadvantage of flat knitting machine in commercial operation heretofore that their output was smaller than that of circular knitting machines of comparable size and cost because of inherent idle movements of the knitting carriage.

It has been attempted heretofore to increase the output of a flat knitting machine by arranging two pairs of needle beds along a loop-shaped path in which knitting carriages are moved one behind the other by means-of an endless chain. In this arrangement, the rhythm of patterns and the output are determined by the number of knitting carriages.

Each carriage of the known arrangement is provided with spools of differently colored yarns and with complex control devices for switching from yarn of one color to another color in order to permit a change in color independently of the sequence of carriages. In

complex patterns and for producing a variety of patterns in successive knitted pieces, yarns of many colors comodated on the chain correspondingly small. Moreover, each carriage needs to be equipped with a complex control mechanism for operating movable cams. These carriages are costly to build and to maintain in operating condition.

If the knitting machine is tobe capable of transferring stitches between needles, as is needed for narrowing a knitted fabric, and of similar operations other than the forming of the usual knitted stitches, special carriages must be attached to the drive chain and moved along the carriage path continuously even while not being needed, and occupy space that could otherwise be used for knitting carriages. If the yarn on one bobbin of one carriage is exhausted, the entire machine must be stopped and a full bobbin substituted for the empty one.

It is the primary object of the invention to provide a flat knitting machine capable of achieving the mode of operation of a circular knitting machine and the advantages inherent in such operation while avoiding the shortcomings of the afore-described multiple-carriage arrangement.

With these and other objects in view, as will hereinaf ter become apparent,'the invention provides a multiple-bed, multiple-carriage machine with a holding area adjacent the loop shaped carriage path, and with a I switching mechanism capable of moving individual carriages from the path to the holding area and from the holding area to the path in any desired sequence while other carriages continue their normal movement along the path.

Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment when considered in connection with the appended drawing in which:

FIG. I shows a knitting machine of the invention in fragmentary, side elevational section on the line I l in FIG. 2, but on a larger scale than in FIG. 2;

FIG. 2 illustrates the central portion of the knitting machine in front elevation;

FIG. 3 shows the apparatus of FIG..2 in top plan view;

FIG. 4 and 5 show a terminal portion of the knitting machine in views respectively corresponding to those of FIGS. 2 and 3;

FIGS. 6 and 7 illustrate yarn carriers for the carriages of the knitting machine in side elevation and in respective operating conditions;

FIG. 8 shows elements of the apparatus of FIGS. 4 and 5 on a greatly enlarged scale;

FIG. 9 shows another detail of the apparatus of FIG. 4 on a larger scale;

FIG. 10 illustrates yet another detail of the apparatus of FIG. 5 on a larger scale; I

FIG. 11 shows another portion of the knitting maspectively; and

. FIG. I2 is a somewhat diagrammatic, enlarged view of a detail of FIG. 11.

FIG. 13 is a schematic drawing, in detached contact form, of the control circuit for the knitting machine.

Referring now to the drawing in detail, and initially to FIGS. 1 to 3, there are seen six pairs of straight needle beds 1 6 mounted on fixedly connected frames 9 15 by means of brackets 7, 8, 25, 26, 27, 28. The pairs of needle beds 1, 3, 5 are longitudinally aligned'in a first, straight row, and the pairs of needle beds 2, 4, 6 are. aligned in a second straight row spacedly juxtaposed and parallel to the first row in a common horizontal plane. The needle beds in each pair converge upward in an inverted V-arrangement, as is conventional in flat knitting machines. The apparatus described so far combines the needle beds, supporting structure, and associated elements, not explicitly shown, of six conventional knitting machines.

Numerous carriages I6 are arranged for individual sliding movement on guide rails I7, 18 above the first row of needle beds and on guide rails I9, 20 above the second row. In the normal operating condition of the apparatus, the several carriages l6 abuttingly engage each other on each pair of guide rails, as is best seen in FIGS. 2 and 3. As is shown in FIG. 1, ball bearings 21 on the guide rails reduce friction between the carriages and the rails to a minimum. Each carriage seen in FIG. I is equipped with a single fixed carrier 22 for a single yarn bobbin 23, and with a yarn guide 24 for feeding the yarn 48 from the bobbin 23 to the knitting needles in the beds 1 6 in a basically conventional manner. The carriages are also equipped with cam boxes, not shown in detail, whose cams operate the needles in the needle beds in a conventional manner. Electrical circuits in the carriages I6 are connected with stationary circuits of the knitting machine by brushes 55 mounted on each carriage for engagement with contacts mounted on the knitting machine frame by means of insulators, not shown in FIG. 1. As will presently become apparent, the brushes illustrated in FIG. 1 are merely representative of multiple electrical connections between each carriage and stationary parts of the apparatus. 7

The carriages 16 are moved along the needle beds by means of short link chains 29, 30 respectively trained over two pairs 31,32 of sprockets which rotate in unison about respective vertical axes between the two rows of needle beds, each pair of sprockets being interposed between the terminal portions of the two rows of needle beds in such a manner that the chains 29, 30 engage the carriage 16 and push the engaged carriages inward of one row and out of the other row, the carriages, when located between the pairs of sprockets, being moved along the guide rails 17-20 by subsequent carriages. The sprockets 31, 32 are driven by the main drive motor of the machine through a transmission in aconventional manner, not illustrated. A box 66 on the frame 9 encloses electronic and electricial switching and control gear, as will be discussed in more detail hereinafter.

The straight guide rails associated with the two rows of needle beds are connected by devices which'lead the carriages 16 between the straight portions of their paths in multiple. loops, as is shown for one side of the apparatus in FIGS. 4 and 5, the devices illustrated being duplicated at the other ends of the guide rails in a manner not separately shown.

The guide rails 17 20 extend beyond the needle beds and a multiple sprocket 71 from which three endless link chains 70 extend to respective sprockets 72 spaced vertically along a common drive shaft, not

shown, on three levels of which the central one is in the plane of the sprockets 31,32, the chains leading to the upper. and lower levels being trained over guide pulleys 72' only partly shown in FIG. 4 for the sake of clarity. The chains 70 are driven by the afore-mentioned motor at a higher uniform speed than that of the chains 29, 30. r

The carriages l6 pushed to the ends of the associated guide rails 17-20 are selected and directed to the proper levels by a guide ramp 47 cantilevered on a pivot 65 as is better seen in FIG. 9. The ramp 47 is' linkedto the armature of a solenoid 46 having two separate windings and a spring (not shown) which normally holds the ramp 47 in the illustrated position in which it guides the carriages l6 driven by the central chain 70 to the central level of the loop arrangement. When one of the windings in the solenoid 46 is energized, the ramp 47 is pivoted toward the lower level, and it is pivoted toward the upper level when the other, non-illustrated winding of the solenoid 46 receives current.

The current supply to the windings in the solenoid 46 is controlled by relays in the control box 66 in response to signals generated by the moving carriages 16. FIG.

[2 shows a lower corner portion 69 of a carriage l6.

Paired openings 74, 75, 76 provide sockets for engagement with pins on a small permanent pagnet 77 at three vertical distances from the lower edge 73 of the carriage. The stationary machine frame carries three switches 78, 79, 80 respectively aligned with the levels of the sockets 74, 75, 76 of the carriages l6 closely adjacent the carriage path immediately ahead of the ramp 47. The switches 78 90 have a fixed contact and a ferrous spring contact enclosed in an evacuated envelope, and close respective circuits when a magnet 77 passes on the appropriate level.

As is indicated in FIG. 11 by letters r, g, w, the carriages 16 are provided with bobbins 23 of yarn 48 which may be red or green or white. The magnets 77 are set in the sockets 76 when the yarn on the carriage is red, in sockets for green yarn, and in sockets 74 for white yarn. The switches 80, 79, 78 are thus closed in response to the color indicated by the position of the magnet 7 and transmit signals to non-illustrated relay circuits in the control box 66 which operate the solenoid 46 in such a manner as to send all carriages carrying red yarn to the upper level, carriages with green yarn to the central level, and carriages with white yarn to the lowermost level. It will be appreciated that more than three levels or fewer levels may be provided for handling varieties of yarn that'is to be knitted into a fabric, the several types of yarn differing from each other by color or other properties.

As shown in FIGS. 4 and 10 for the uppermost level, the carriages 16 are transferred by the associated chain 70 over a straight rail section 20' to a switch 86 operated by a solenoid 85. Another straight rail section 20 further leads the carriages l6 driven by the chain 70 to a turntable 36 equipped with pegs, not shown, which engage the carriages and'hold them onthe turntable in circumferentially ofiset positions. Limit switches .84 are circumferentially distributed on the turntable 36 for engagement by carriages 16. The limit switches 84 are connected with the central control system in the control box 66 to energize the solenoid 85 and to move the switch 86 into the illustrated position when the turntable 36 isvfilled with carriages. 16 carrying red yarnand the switches 84 generate a corresponding signal in a known manner, for example, by shorting respective series-connected resistors and thereby reducing the resistance of a signalling circuit to a threshold value indicative of the filling of the .tumtable. The turntableis driven in steps corresponding to the circumferential spacing of the limit switches 84 and the corresponding spacing of the non-illustrated pegs by an electric motor 81 (FIG. 4).

Carriages deflected from the turntable 36 by the switch 86 are moved along storage rails 87 by a chain 62 driven at the continuous speed of the chain 70 by sprockets 89, 90, the sprocket 89 being coaxial with the turntable 36 and driven by the afore-mentioned main drive motor. The manner in which the carriages engage the chain 62 is shown in FIG. 8. Pins 64 projecting from each link of the chain 62 provide abutments for a lever 63 mounted on each carriage, not otherwise shown in FIG. 8, as long as the lever is pivoted counterclockwise into the illustrated position by a solenoid 88 on the carriage. Current carrying rails, omitted from the drawing for the sake of clarity extend from the switch 86 along the rails 87 almost to a position occupied by a carriage 16a in the view of FIG.5.

The rails are engaged by brushes on each carriage in the manner seen in FIGS. 1, 6, and 7 to energize the solenoid 88.. When the solenoid is deenergized, a helical tension spring 88a lifts the lever 63 out of range of the pins 64. As long as the non-illustrated rails are provided with current and connected to the solen id 38, the carriages 16 move along the rails 87. A limit switch, not shown, but closely similar to the switches 84 described above, cuts the non-illustrated rails from the awrren-s supply when a carriage occupies the position 16b so that the rail 87 normally holds a reserve of up to seven carriages ready for return to service.

A switch 92 operated by a solenoid 91 connects the discharge portions of the turntable 36 and of the storage rail 87. A programming unit in the control box 66, not illustrated, but closely similar to a conventional Jacquard mechanism, energizes the motor 81 for turning the turntable 36 through one step and for thereby discharging one carriage 16 carrying red yarn when a punched card in the mechanism or an analog thereof calls for a course of red yarn in the fabrics being knitted on the several needle beds 1-6, and when the switches 84 indicate that the turntable 36 is fully set with carriages. If the switches 84 indicate that the turntable 36 is not filled, the control circuit in the box 66 energizes the solenoid 88 on the carriage 16b to connect the carriage to the chain 62 until it is within range of the chain 70, the necessary contact rails having been omitted from the drawing. The solenoid 91 is simultaneously energized or not energized as may be needed for guiding a carriage with red yarn toward a ramp 93, analogous to the aforedescribed ramp 47, from the turntable 36 or from the storage or holding rail 87, and the ramp 93 is pivoted to receive the red carriage in response to a signal from the control box 66.

The intermediate and lower levels for carriages carrying green or white yarn are equipped and operated in the same manner as described above for the top level. Their turntables 37, 38 are driven by respective electric motors 82, 83.

As is shown in FIGS. 6 and 7, the yarn carrier 22 on each carriage 16 is equipped with an automatic signalling device for indicating the imminent exhaustion of yarn 48. The yarn is wound on a conical cardboard tube 49, and the bobbin essentially consisting of the tube and the yarn wound thereon is set on a conical, fixed core on the carrier 22 in such a manner that a plunger 50 guided in a radial opening of the core enters an aligned opening in the tube 49, as is shown in FIG. 6. The plunger 50 is biased in a radially outward direction by a helical compression spring 52 in a switch housing 51 mounted on the carried 22 in a manner not seen in the drawing.

The tightly wound yarn 48 on a full bobbin offers sufficient resistance to the plunger 50, as shown in FIG. 6, to compress the spring 52, and thereby to flex a spring contact 53 out of engagement with a fixed contact 54 in the housing 51. The contacts 53, 54 are respectively connected with the two brushes 55 mentioned before. As the yarn 48 is depleted during knitting, the thinning yarn layer cannot resist the pressure of the plunger 50, and the contacts 53, 54 are engaged, as shown in FIG. 7, thereby closing a circuit between the stationary contacts 67, 68 when the brushes 55 engage the contacts 67, 68 which are connected with non-illustrated circuitry in the control box 66.

A first set of contacts 67, 68 is located ahead of the switch 86, as is shown in FIG. 5. When these contacts are connected by the brushes of an approaching empty carriage 16, a delay circuit in the box 66 shifts the switch 86 to the illustrated position to shift the empty carriage to the storage rail 87 suitable for the color of the yarn on the carriage. A second set of stationary contacts 67 68 is located at the storage rail 87 immediately ahead of a switch 95 operated by a solenoid 94. A signal transmitted from the contacts 67', 68 to the control box 66 causes the solenoid 94 to be energized and the empty carriage to be switched to a siding 96, the carriage being uncoupled from the driving chain 62 as soon as it leavesthe storage rail 87.

An operator may replace the empty yarn bobbin on the carriage while the same is on the siding 96, and then manually return the carriage to the storage rail 87 by way of another switch 99 operated by a solenoid 98 when a push button switch 97 closes the energizing circuit of the solenoid. The siding 96 described with reference to the top level of the apparatus of FIGS. 4 and 5 is duplicated on the central and lower levels together with the associated switches and control circuits. Obviously, one of the levels may be used for carriages equipped with narrowing devices or other special equipment, and the references to variously colored yarn in the foregoing description will be understood to be by way of example only since the illustrated and described apparatus is not limited to the production of multi-colored knitted fabrics.

As is inherent in its structure, it permits simultaneous knitting of as many fabrics as there are needle beds or pairs of needle beds with carriages which move one behind the other in abutting engagement, are as short as is possible when accomodating necessary earns, a single yarn bobbin, and associated devices, move in one direction only, and may be withdrawn from or inserted into the operating cycle without interfering with the operation of other carriages. Replenishment of yarn and repairs and modifications of carriages may take place without interrupting the knitting operation. The apparatus of the invention thus combines the most significant advantages of circular knitting machines with all advantages of a flat knitting machine.

FIG. 13 illustrates the wiring within control box 66. Each element therein, and its interconnection with other circuit elements, is already illustrated in FIGS. 1 12 and/or functionally described in the specification, with the exception of on-off switch 200, rectifier 201 and fuse 202, which are entirely conventional. Summarizing the operation, when a magnet 77 in a carriage 16 passes by, and closes, switch 78, say, relay 78,, will close completing a path through relay contacts 78 -l to the upper winding of solenoid 46. Thus, ramp 47 will assume its uppermost position. In like manner, closure of switch 80 will cause relay 80,, to operate and move ramp 47 to its lower position. However, closure of switch 79 will operate relay 79 A and open contacts 79 I, thus inhibiting actuation of solenoid 46. This results in ramp 47 maintaining, or returning to, the neutral or center position.

As additional carriages 16 are stored in turntable 36, the swtiches 841, 842, etc. successively close, causing switch contacts 84 -1, -l, etc. to switch-in additional resistors R1, R2, etc. When the turntable 36 is fully loaded, relay 84,, will release, thereby closing contacts 86,-1 and energizing solenoid 85, as above described. Solenoid 85 may also be energized if contacts 53, 54 on a carriage 16 are closed while the carriage is positioned such that brushes 55 are opposite contacts 67, 68, however delay circuit 206 is interposed in the closure path to provide sufficient delay to allow for physical transport of the carriage 16 to the switch 86. Solenoid 88 on a carriage 16 will be actuated, via brushes 55A and contacts 67,, 68A, if contacts 84 -2 are closed, which of course only happens if relay 84A is released and all contacts 845-1, 84 -1 etc., are closed. signifying that turntable36 is full.

Motors 81, 82, and 83 will be energized if the Jacquard type programming unit so dictates and relay 84,. (or 848 or 84 is activated, which corresponds to the condition where turntable 36 is not filled. Solenoid 91, and hence switch 92, is also controlled by relay 84,

etc. via contacts 844-4. Solenoid 98, and hence switch 99, may be manually operated by switch 97, as above 1. In a knitting apparatus having a plurality of straight, elongated needle beds, a plurality of knitting carriages, and drive means for moving said carriages in a continuous path extending in a closed loop, said needle beds being arranged along said path for sequential cooperation of the needles in said needle beds with said carriages, the improvement which comprises:

a. first switch means in saidspath for deflecting carriages out of said path to a'holding area;

b. second switch means for returning deflected carriages from said holding area to said path; and

c. control means for operating said switch means and for thereby retaining selected carriages in said path, and for deflecting other carriages to said holding area.

2. In an apparatus as set forth in claim 1, guide means engaging said carriages for guiding said carriages in said path while freely movable relative to said guide means, said drive means including engaging means for engaging the carriages in a portion of said path only and for moving the engaged carriages along said por tion, whereby the carriages freely movable in other portions of said path are moved by abutting cooperation with the carriages engaged by said engaging means.

3. In an apparatus as set forth in claim 2, said engaging means moving said carriages in said path at a uniform speed.

4. In an apparatus as set forth in claim 2, said needle beds being arranged in two rows, said engaging means including a continuous chain, means for moving respective portions of said chain longitudinally of terminal needle beds in said rows in opposite directions, and means for securing respective carriages to said portions of said chain for movement therewith.

5. In an apparatus as set forth in claim 1, said beds being arranged in two juxtaposed rows of longitudinally aligned needle beds, guide means for guiding said carriages in respective portions of said path elongated along said rows, said portion of said path extending in a common direction, and a turntable defining another portion of said path connecting said elongated portions. A

6. Man apparatus as set forth in claim 5, another turntable, and selector means interposed between said elongated portions of said path and said turntables for guiding a first selected carriage from one of said elongated portions to one of said turntables and for guiding another selected carriage from said one elongated portion to the other turntable, and for transferring said selected carriages from the respective turntables to the other elongated portion of said path.

7. In an apparatus as set forth in claim 6, said first and second switch means being interposed between said turntable and said elongated portions of said path respectively.

8. In an apparatus as set forth in claim 6, signal generating means on each of said carriages, and means for transmitting the signal generated by said generating means to said selector means for operating the selector means in response to said signal.

9. In an apparatus as set forth in claim 5, signal generating means on said turntable for generating a signal in response to the presence of a predetermined number of said carriages on said turntable, and means for transmitting said signal to said first switch means for operating the same in response to said signal.

10. In an apparatus as set forth in claim 1, signal generating means on each of said carriages, and means for transmitting the signal generated by said generating means to said first switch means for operating the same in response to said signal. 

1. In a knitting apparatus having a plurality of straight, elongated needle beds, a plurality of knitting carriages, and drive means for moving said carriages in a continuous path extending in a closed loop, said needle beds being arranged along said path for sequential cooperation of the needles in said needle beds with said carriages, the improvement which comprises: a. first switch means in said path for deflecting carriages out of said path to a holding area; b. second switch means for returning deflected carriages from said holding area to said path; and c. control means for operating said switch means and for thereby retaining selected carriages in said path, and for deflecting other carriages to said holding area,
 2. In an apparatus as set forth in claim 1, guide means engaging said carriages for guiding said carriages in said path while freely movable relative to said guide means, said drive means including engaging means for engaging the carriages in a portion of said path only and for moving the engaged carriages along said portion, whereby the carriages freely movable in other portions of said path are moved by abutting cooperation with the carriages engaged by said engaging means.
 3. In an apparatus as set forth in claim 2, said engaging means moving said carriages in said path at a uniform speed.
 4. In an apparatus as set forth in claim 2, said needle beds being arranged in two rows, said engaging means including a continuous chain, means for moving respective portions of said chain longitudinally of terminal needle beds in said rows in opposite directions, and means for securing respective carriages to said portions of said chain for movement therewith.
 5. In an apparatus as set forth in claim 1, said beds being arranged in two juxtaposed rows of longitudinally aligned needle beds, guide means for guiding said carriages in respective portions of said path elongated along said rows, said portion of said path extending in a common direction, and a turntable defining another portion of said path connecting said elongated portions.
 6. In an apparatus as set forth in claim 5, another turntable, and selector means interposed between said elongated portions of said path and said turntables for guiding a first selected carriage from one of said elongated portions to one of said turntables and for guiding another selected carriage from said one elongated portion to the other turntable, and for transferring said selected carriages from the respective turntables to the other elongated portion of said path.
 7. In an apparatus as set forth in claim 6, said first and second switch means being interposed between said turntable and said elongated portions of said path respectively.
 8. In an apparatus as set forth in claim 6, signal generating means on each of said carriages, and means for transmitting the signal generated by said generating means to said selector means for operating the selector means in response to said signal.
 9. In an apparatus as set forth in claim 5, signal generating means on said turntable for generating a signal in response to the presence of a predetermined number of said carriages on said turntable, and means for transmitting said signal to said first switch means for operating the same in response to said signal.
 10. In an apparatus as set forth in claim 1, signal generating means on each of said carriages, and means for transmitting the signal generated by said generating means to said first switch means for operating the same in response to said signal. 